1. Field of the Invention
The present invention relates to a system for dilatation of a body passage and delivery of a stent into the body passage of a patient, and related methods of using such a system.
2. Description of Related Art
Stents are well-known endoprotheses. A conventional endoprosthetic stent includes a radially-expandable, tubular structure. The tubular structure can expand radially from a compact form for delivery to an expanded form for implantation. Radial expansion of the stent effects implantation into the tissue of a body passage wall being repaired, supported, or bridged. The body passage can include, for example, a body canal, blood vessel, duct, other passage, and the like.
A conventional endoprosthetic stent can be mechanically expansive or self-expansive. A conventional mechanically-expansive stent initially possesses a radially compact form. The stent is loaded onto a delivery system, such as a catheter. Typically, an expandable balloon is positioned in the tubular structure of the stent. After delivering the stent to the region of a body passage being repaired or bridged, the balloon is expanded, thereby implanting the stent onto the passage wall. To expand the stent, the balloon must be connected to a fluid source by means of a lumen or some other tubular structure.
A conventional self-expansive stent initially possesses a radially-expanded form. The stent is compressed radially as it is assembled onto a delivery system. Typically, an outer tubular structure retains the compressed stent until it is delivered to the region of a passage being repaired or bridged. The stent is then released from its compressed state and self-expands to implant onto the passage wall. An expandable balloon is not required to expand the stent. However, in cases where a stricture of the passage is difficult to repair or bridge, a physician may use a balloon to assist with expansion of the deployed stent.
Generally, when a balloon is used to assist with expansion of a self-expanding stent, the conventional stent delivery system is removed after the stent is successfully deployed. Then, either a separate single-use balloon catheter or a second delivery system having an expandable balloon is delivered to the site of the stent. In either event, a physician would be slowed by this process of removing the stent delivery system and delivering the balloon.
Conventional stent delivery systems generally include a minimal transverse dimension so that a distal end of the delivery system can be navigated through and along a patient's lumens, either in a percutaneous insertion procedure, through the working channel of an endoscope or laparoscope, or next to a scope. Often times, physicians use a delivery system in combination with a medical guide wire. Typically, in transluminal procedures, the physician directs a guide wire through narrow passages in a patient's body using a steering mechanism provided at a proximal end outside of the body. The physician monitors the travel and position of a distal end of the guide wire by a fluoroscope or other known method or device. Once the distal end of the guide wire reaches a desired position, the steering mechanism is removed and the delivery system is directed into the passage along the guide wire. Other procedures for directing catheters or similar devices into larger passages of the body, such as the esophagus, are also well known.
In some cases, it is desirable to dilate the body passage prior to deploying a stent in the passage, especially in the case of a stricture in the passage. In such a case, a balloon catheter is directed into the passage along the guide wire and the balloon is inflated to dilate the stricture in the body passage.
Thus, use of a conventional delivery system for a self-expanding stent in combination with a guide wire, a pre-deployment dilatation balloon, and a post-deployment expandable balloon, would require the following time-consuming procedures: delivery of the guide wire; delivery and activation of the pre-deployment balloon to dilate the passage; removal of the pre-deployment balloon; delivery of the stent deployment system and deployment of the stent; removal of the stent delivery system; delivery and activation of an expandable balloon device to assist in expansion of the stent; and removal of the expandable balloon device and guide wire. The repeated insertion and removal of delivery systems is cumbersome, prolongs the procedure, increases the trauma and risk to the patient, and increases costs.